Reflex Lab Analysis

In this lab, we basically tested different reflexes and observed differences in reaction times. A reflex is defined as an unlearned, automatic reaction to a stimulus. Sometimes, when there is a stimulus, a quick response is needed, so the brain is actually not involved with coordinating the response. Instead, the sensory neurons pass into the spinal chord instead and produce a quick reflex response that doesn't need the brain. We looked at many reflexes today, and below is a recap and CER on each experiment.

1. Photopupillary Reflex

In this experiment, one partner covered one eye from a light for several minutes, then the eye was uncovered, a light was shined into the eye, and observations in pupil size change were recorded. The pupils would adjust in size based on the amount of light it is receiving. When we performed this experiment, after a period of darkness followed by sudden bright light, we observed that the pupil would become smaller than the other eye. This change in pupil size is called pupil dilation, and is due to the fact that different amounts of light into the eye to provide better vision in environments with more or less light. This is likely a very useful tool for us and our ancestors as better vision allows us to recognize potential dangers quicker and make a safe decision.

2. Knee Jerk Reflex

This was one of the classic reflex experiments where you tap the knee with a knee hammer and see how fast the reflex occurs, in which the leg kicks out. We then had to do at least 30 squats and repeat the experiment. We recorded and compared our observations. Our claim is that the knee reflex is more prominent and is faster in the trial without doing air squats prior to the testing. When we did the experiment, my leg kicked out a lot harder and higher in the first trial, and in the second trial, my leg kicked much lower and it was noticeably slower. The reason for this is because after you do squats, the muscles in your leg become tired, so the reflex does not occur as quickly.

3. Blink Reflex

This was also another classic reflex to test. It involved holding a clear sheet (in our case plastic wrap) in front of our faces while a cotton ball was thrown at our face. The observations were then recorded. When an object is thrown toward the face, in particular the upper region of the face around the eyes, the person will blink in response. This was observed in our experiment as in both trials, the tested subject blinked when the cotton ball was thrown at the face. This is due to the body's natural inclination to protect its eyes from harm as they are vital organs and important for survival. By blinking and closing the eyes, it lessens the chance that something harmful will come in direct contact with the eye.

4. Babe, what's your sign?

This was the most interesting lab to me as I had never done this before. In this lab one person would run a pen with firm pressure down the tested subject's foot. We then observed the response. The toes clench together when a pen is run down the foot, and if it doesn't, then there is a possibility of nerve damage. Our evidence is that when we did the experiment, both of us experienced the toe curling response. This is due to a body response in which when you are about to step on something that can be harmful, the toes try to curl away to avoid it. If the toes remain spread out, then there is a much higher chance of damaging the foot.

5. How fast are you? (Reaction Time)

In this experiment, we tested reaction time rather than a body reflex. One partner would hold a yardstick with the other person's hand just below it. The yardstick was dropped within 5 seconds and then the measurement of where the person caught it was recorded. This process was repeated three times and then three more times while texting,  and the measurements were then converted to reaction times. The reaction time was much faster when the person catching the yardstick is not distracted by texting. Although my reaction time remained the same with and without texting (from 0.23 seconds to 0.23 seconds), that was a discrepancy. In our class data, we observed the trend where texting heavily increased reaction time, as it is clearly visible in the graph below. The male and female average response without texting was around 0.18 seconds, while the average with texting increased to around 0.26 seconds. The reaction time is slower when you text because your brain is incapable of multitasking. This translates to texting while driving, and suggests that texting while driving is very dangerous as a person will react much slower in a dangerous situation. There is also a picture of catching the yardstick at one of the trials.

Brain Map!

Your Brain Map: 84 Strategies for Accelerated Learning

Cerebral Cortex

1.     What do the frontal lobes do?

The frontal lobes control behavior, personality, problem solving, language, memory, impulse, and judgment.

2.     What is the relationship between selective attention and learning?

Selective attention is how selective you are when remembering information, and it translates to intelligence levels. It also improves your memory capacity because it allows prioritization of more important information.

3.     What is the last part of your brain to develop and what can you do to prevent it from deteriorating?

The frontal lobe develops last, and one way to prevent it from deteriorating as quickly is to perform mental exercises that engage with the environment and transform information, rather than memorizing the information.

4.     What does the neo cortex do?

It helps with spatial awareness, fine motor skills, environment receptiveness(when compared to other areas of the brain), body navigation, and controlling the senses.

5.     What is the role of the pre frontal cortex?

It controls personality and behavior in social settings, and also organizes and aligns actions and thoughts with goals.

6.     What do we know about the pre frontal cortex’s relationship with multitasking?

The pre frontal cortex actually contains a “central bottleneck,” which prevents you from doing more than one thing at a time and thus multitasking. When you “multitask,” your brain is simply jumping from one activity to another very quickly and it in turn lowers the quality of everything you are multitasking on.

7.     Which part of the brain is associated with speech and language development?  Give an interesting fact about this region.

The Broca’s area is associated with speech and language development. One interesting fact about this area is that speaking more than one language, in example being bilingual or trilingual, provides large benefits to the brain as it forces your brain to keep both languages active at all times, even if only one is in use.

8.     Which part of your brain is responsible for thinking the following: “Is it hot in here or is it just me?”

The part of your brain responsible is the somatosensory cortex, as it helps the body to respond to touch, pain, and varying temperatures.

9.     What does your visual cortex do for you?

This allows you to see differences in colors and other specific  visual features, and also allows you to recognize different faces.

10. State three interesting or significant facts about your occipital lobe.

One interesting fact about the occipital lobe is that the it functions in an unexpected “crossed” manner, where the right side works for the left eye, and the left side works for the right eye. Another interesting fact is that it helps in visualization; some studies have shown that visualization in great accuracy can translate to a similar performance in real life. Finally, it allows you to imagine things and process both short and long term memories.

11. What would happen if your temporal lobes were damaged?

The most important part of the temporal lobe that you cannot damage is the medial temporal lobe. This is because that region is responsible for long term memory, so if that part was damaged, you wouldn’t be able to remember things and would need to constantly relearn different tasks.

12. What is your “fast brain” and what does it do?

Your fast brain is the eye field. It basically allows your brain to interpret all the information it receives due to the eye moving rapidly and picking up a lot of information quickly.

Neuron

13. State 3 things that you could do that would influence your synapses, and have a positive affect on your life and health.

Synapses are affected by omega fatty acids, so in turn, by exercising and eating a diet with lots of omega three acid containing foods, your brain function can be improved.

14. What is the relationship between multi-sensory or multi-modal learning and your dendrites?

Dendrites and multi-sensory and multi-modal learning are related as dendrites are required in cross referencing data in the brain to convert new knowledge into learned knowledge.

15. How does “big picture thinking” and mnemonics affect dendrites and/or learning?

By utilizing big picture thinking and mnemonics, we are able to draw more connections to things we already know, which helps us retain the information and learn it more effectively. It allows us to easier break down a big picture into smaller, more easily understood part. This causes the dendrites to better communicate to help us retain the information effectively and improve recollection.

16. Describe a neurotransmitter that you feel is very important.  Justify your reasoning.

One important neurotransmitter is dopamine because it teaches us what is good to do, and what is not. For example, when we experience something enjoyable, such as winning a competition, we are then motivated to repeat the action again, which leads to success in pursuing areas of interest.

Limbic System

17. What does the corpus callosum do?

The corpus callosum is in between the right and left hemispheres of the brain, and facilitates communication between the two hemispheres, including sensory, cognitive, and motor functions. It is also involved with language structure and reading/comprehension.

18. What is the relationship between music and the corpus callosum?

Extensive studying in music strengthens the communication between the two hemispheres via the corpus callosum. In one study, children who played music for around 3 hours every week had a 25% increase in their corpus callosum.

19. Why is the thalamus important?

The thalamus is important because it regulates sleep cycles and awakeness. It also processes and sends information from the senses to the cortex, and deals with memory, attention, emotion, and consciousness.

Relate and Review

Summarize what you learned from this tutorial.  Relate what you learned to your everyday life and how you can make it better.  Use at least 5 of the bolded words from the questions.  5-sentence minimum. You may use the back of this if needed.

An interactive infographic by Open Colleges

This tutorial discussed different parts of the brain and how each functions, as well as why a lot of structures are important. One part that I thought was really interesting was the information on the corpus callosum, which stated how with prolonged practice in music, the corpus callosum actually increases in size. It made me wonder two things. Firstly, I was curious as to what about music specifically made the corpus callosum larger. Secondly, I was curious as to whether there were any similar activities that increase the corpus callosum, and whether other parts of the brain could increase in size as well due to doing certain activities. The tutorial also taught me that the thalamus plays a huge part in sleep cycles, so I assume that jet lag is heavily associated with that part as the hormones released are likely affected. The frontal lobe is also very interesting because it contains the prefrontal cortex and the neo cortex. The prefrontal cortex controls personality and behavior in social settings, and also organizes and aligns actions and thoughts with goals. The neo cortex helps with spatial awareness, fine motor skills, environment receptiveness (when compared to other areas of the brain), body navigation, and controlling the senses.

Brain Dissection Questions

1. Here is a picture of our dissected sheep brain with the labeled parts! The posterior side is black, the anterior side is white, the cerebrum is yellow, the cerebellum is green, and the brain stem is pink.

2.

Anterior: The anterior part of the brain is the most front part, and is comprised of the frontal lobe.
Anterior function: The frontal lobe is responsible for intellectual activities such as personality, the ability to empathize, organization, and behavior.

Posterior: The posterior part of the brain is the most back part of the brain and is comprised of the occipital lobe (and brain stem).
Posterior Function: The occipital lobe is responsible for vision.

Cerebrum: Comprised of the two separated hemispheres (left and right).
Cerebrum Function: The cerebrum integrates complex sensory and neural functions that control voluntary activities in the body.

Cerebellum: located at the bottom of the skull near the brain stem.
Cerebellum Function: The cerebellum regulates balancing and fine motor skills and allows for smooth movement.

Brain Stem: Lowest part of the brain, leads to spinal chord.
Brain Stem Function: The brain stem regulates functions that are autonomic, such as heart rate, consciousness, and blood pressure. It also helps carry signals from the body to the brain.

3. The purpose of the myelin in a neuron is to increase the speed at which an impulse can move along a myelinated fiber. It also provides insulation and protects the neuron.

4. Here is a picture of our cross section. The thalamus is yellow, the optic nerve is green, the medulla oblongata is silver, the pons is white, the midbrain is blue, the corpus callosum is red, and the hypothalamus is black.

5.
Thalamus: relays messages between the lower brain center and cerebral cortex.
optic nerve: transfer visual information from retina to occipital lobe.
medulla oblongata: controls heart rate and respiration rate.
pons: regulates respiration, links cerebrum and cerebellum.
midbrain: responsible for vision, awakeness, hearing, and motor control.
corpus callosum: between left and right hemispheres, allows for communication between the two hemispheres.
hypothalamus: linked to emotions and eating, controls endocrine system.

6. Here is a picture of the drawing of our cross section; the gray matter has been shaded and labeled, as well as the parts with white matter.